Abstract
Purpose:
To investigate the relationship among functional visual field, functional visual acuity, and the score of Schirmer test in elderly drivers with normal cognitive status.
Methods:
Thirty eyes of 30 healthy adult volunteers (22 males and 8 females), who had no ophthalmic diseases other than refractive errors, had a normal cognitive status (23 and more with mini-mental state examination-Japanese (MMSE-J)), and drove at least once a week, were enrolled in this study. All subjects underwent slit-lamp microscopy, binocular corrected distant visual acuity (CDVA), binocular distant functional visual acuity (FVA) using the FVA measurement device Kowa AS-28 (Kowa Co Ltd, Aichi, Japan), tear break up time (BUT), Schirmer test without topical anesthesia, and functional visual field using Visual Field with Inhibitory Tasks (VFIT). VFIT is a computer software developed in 2004 to detect functional visual field for healthy subjects and cerebral injury patients. This test measures a person’s ability to recognize one object in the peripheral visual field while watching a point of regard at the center of the screen. The percentage of correct answers in VFIT is already known to have a significant correlation with the rating of driving skills using an actual vehicle (Fujita.Y et. al. Sagyoryohou [in Japanese], 2012). Spearman’s rank correlation coefficient was used to investigate the relationship between the percentage of correct answer of VFIT, CDVA and FVA.
Results:
The mean age of the subjects was 66.8±4.4 years ( range: 60 to 77 years). Mean CDVA and FVA in log MAR were -0.11±0.12and -0.03±0.14, respectively. The mean percentage of correct answers in VFIT was 86.6±11.3. The mean score of Schirmer test was 8.0±6.3 mm. The mean BUT was 3.4±2.8 seconds. The percentage of correct answers in VFIT significantly correlated with FVA (r = -0.470 and P = 0.009), but not with CDVA.
Conclusions:
FVA has the potential to effectively evaluate the elderly driving skills.
Keywords: 753 vision and action •
754 visual acuity